ability to inject default errorHandler

[minipai]

I need a ability to inject a default error handler, like angular's $http can do.
So I modify a bit to let fetchival can accept errorhandler.
My use case is return to /login page whenever status is 401.

var errorhandler = function(response) {
    if (response.status === 401) {
        Cookies.expire('user');
        Cookies.expire('access_token');
        window.location = '/';
    };
}

var API = {
    Orders: fetchival('/api/orders', fetchOptions, errorhandler),
    RefNumber: fetchival('/api/ref_numbers', fetchOptions, errorhandler),
    Stores: fetchival( '/stores', fetchOptions, errorhandler),
}